Before you start pulling parts off the engine, I wouldn't get too worried about her. She started and responded to the throttle. Did she make any nasty noises? If not, good enough. As a general rule of thumb, if a diesel starts easily, she is in decent shape. It is when she won't start easily that you have to start looking at fuel and/or compression related issues, like rings, valves, pumps injectors etc.
Replace the impeller and call up Torresens and order one of these:
Yanmar 2GM Major Kit Torresen
just for peace of mind. Jones's Rule #32 of Boat Maintenance- you will never require any of the spare parts you have on board, but the one part you don't have is always the one that fails, so always stock one of everything.